X-Git-Url: http://git.phpeclipse.com

diff --git a/net.sourceforge.phpeclipse/src/net/sourceforge/phpdt/internal/ui/text/BufferedDocumentScanner.java b/net.sourceforge.phpeclipse/src/net/sourceforge/phpdt/internal/ui/text/BufferedDocumentScanner.java
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--- /dev/null
+++ b/net.sourceforge.phpeclipse/src/net/sourceforge/phpdt/internal/ui/text/BufferedDocumentScanner.java
@@ -0,0 +1,151 @@
+package net.sourceforge.phpdt.internal.ui.text;
+
+/*
+ * (c) Copyright IBM Corp. 2000, 2001.
+ * All Rights Reserved.
+ */
+
+import org.eclipse.jface.text.BadLocationException;
+import org.eclipse.jface.text.IDocument;
+import org.eclipse.jface.text.rules.ICharacterScanner;
+import org.eclipse.jface.util.Assert;
+
+
+
+/**
+ * A buffered document scanner. The buffer always contains a section 
+ * of a fixed size of the document to be scanned.
+ */
+
+public final class BufferedDocumentScanner implements ICharacterScanner {
+
+	/** The document being scanned. */
+	private IDocument fDocument;
+	/** The offset of the document range to scan. */
+	private int fRangeOffset;
+	/** The length of the document range to scan. */
+	private int fRangeLength;
+	/** The delimiters of the document. */
+	private char[][] fDelimiters;
+
+	/** The buffer. */
+	private final char[] fBuffer;
+	/** The offset of the buffer within the document. */
+	private int fBufferOffset;
+	/** The valid length of the buffer for access. */
+	private int fBufferLength;
+	/** The offset of the scanner within the buffer. */
+	private int fOffset;
+
+	
+	/**
+	 * Creates a new buffered document scanner.
+	 * The buffer size is set to the given number of characters.
+	 * 
+	 * @param size the buffer size
+	 */
+	public BufferedDocumentScanner(int size) {
+		Assert.isTrue(size >= 1);
+		fBuffer= new char[size];
+	}
+
+	/**
+	 * Fills the buffer with the contens of the document starting at the given offset.
+	 *
+	 * @param offset the document offset at which the buffer starts
+	 */
+	private final void updateBuffer(int offset) {
+
+		fBufferOffset= offset;
+		
+		if (fBufferOffset + fBuffer.length > fRangeOffset + fRangeLength)
+			fBufferLength= fRangeLength - (fBufferOffset - fRangeOffset);
+		else
+			fBufferLength= fBuffer.length;
+
+		try {
+			final String content= fDocument.get(fBufferOffset, fBufferLength);
+			content.getChars(0, fBufferLength, fBuffer, 0);
+		} catch (BadLocationException e) {
+		}
+	}
+
+	/**
+	 * Configures the scanner by providing access to the document range over which to scan.
+	 *
+	 * @param document the document to scan
+	 * @param offset the offset of the document range to scan
+	 * @param length the length of the document range to scan
+	 */
+	public final void setRange(IDocument document, int offset, int length) {
+
+		fDocument= document;
+		fRangeOffset= offset;
+		fRangeLength= length;
+
+		String[] delimiters= document.getLegalLineDelimiters();
+		fDelimiters= new char[delimiters.length][];
+		for (int i= 0; i < delimiters.length; i++)
+			fDelimiters[i]= delimiters[i].toCharArray();
+
+		updateBuffer(offset);
+		fOffset= 0;
+	}
+
+	/*
+	 * @see ICharacterScanner#read()
+	 */
+	public final int read() {
+
+		if (fOffset == fBufferLength) {
+			if (fBufferOffset + fBufferLength == fDocument.getLength())
+				return EOF;
+			else {
+				updateBuffer(fBufferOffset + fBufferLength);
+				fOffset= 0;
+			}
+		}
+
+		return fBuffer[fOffset++];
+	}
+
+	/*
+	 * @see ICharacterScanner#unread
+	 */
+	public final void unread() {
+
+		if (fOffset == 0) {
+			if (fBufferOffset == fRangeOffset) {
+				// error: BOF
+			} else {
+				updateBuffer(fBufferOffset - fBuffer.length);
+				fOffset= fBuffer.length - 1;
+			}
+		} else {			
+			--fOffset;
+		}
+	}
+
+	/*
+	 * @see ICharacterScanner#getColumn()
+	 */
+	public final int getColumn() {
+
+		try {
+			final int offset= fBufferOffset + fOffset;
+			final int line= fDocument.getLineOfOffset(offset);
+			final int start= fDocument.getLineOffset(line);
+			return offset - start;
+		} catch (BadLocationException e) {
+		}
+
+		return -1;
+	}
+
+	/*
+	 * @see ICharacterScanner#getLegalLineDelimiters()
+	 */
+	public final char[][] getLegalLineDelimiters() {
+		return fDelimiters;
+	}
+}
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